After a meeting with Interim President Ba Mamadou, Deye told reporters that the electoral commission is performing its duties with neutrality and transparency, ensuring equal treatment for all candidates.

Deye says there will be more than 250 electoral observers on hand to monitor the vote.

It is a contest to restore constitutional order in Mauritania after General Mohamed Ould Abdel Aziz toppled the country's first freely-elected leader 11 months ago.

President Sidi Ould Cheikh Abdallahi formally resigned last month as part of a power-sharing deal negotiated in neighboring Senegal. The deal led to an interim government of military leaders and political opponents that is to yield power following this election.

Aziz resigned his military commission to contest the vote. He has been running longer than any of the other candidates, as he campaigned for nearly one month before an earlier scheduled vote that he agreed to postpone as part of the power-sharing deal.

Aziz is being challenged by another former military leader who organized the election that chose Mr. Abdallahi. Ely Ould Mohamed Vall is the only Mauritanian military ruler to give up power to civilians. He has considerable administrative and defense experience, including 20 years as director of national security.

The country's main opposition leader is also a candidate. Ahmed Ould Dadah's Alliance of Democratic Forces holds the most seats in parliament. He finished second to Mr. Abdallahi in the last election and hopes to win the backing of many Abdallahi supporters as the former president is not a candidate.

If no one wins more than half the vote Saturday, Mauritania's power-sharing deal calls for a second round of balloting August 1.